Context Components of the insulin resistance syndrome (IRS), including obesity, glucose intolerance, hypertension, and dyslipidemia, are major risk factors for type 2 diabetes and heart disease.Although diet has been postulated to influence IRS, the independent effects of dairy consumption on development of this syndrome have not been investigated. ObjectiveTo examine associations between dairy intake and incidence of IRS, adjusting for confounding lifestyle and dietary factors. DesignThe Coronary Artery Risk Development in Young Adults (CARDIA) study, a population-based prospective study. Setting and ParticipantsGeneral community sample from 4 US metropolitan areas of 3157 black and white adults aged 18 to 30 years who were followed up from 1985-1986 to 1995-1996.Main Outcome Measure Ten-year cumulative incidence of IRS and its association with dairy consumption, measured by diet history interview. ResultsDairy consumption was inversely associated with the incidence of all IRS components among individuals who were overweight (body mass index Ն25 kg/m 2 ) at baseline but not among leaner individuals (body mass index Ͻ25 kg/m 2 ).The adjusted odds of developing IRS (2 or more components) were 72% lower (odds ratio, 0.28; 95% confidence interval, 0.14-0.58)among overweight individuals in the highest (Ն35 times per week, 24/102 individuals) compared with the lowest (Ͻ10 times per week, 85/190 individuals) category of dairy consumption.Each daily occasion of dairy consumption was associated with a 21% lower odds of IRS (odds ratio, 0.79; 95% confidence interval, 0.70-0.88). These associations were similar for blacks and whites and for men and women.Other dietary factors, including macronutrients and micronutrients, did not explain the association between dairy intake and IRS.Conclusions Dietary patterns characterized by increased dairy consumption have a strong inverse association with IRS among overweight adults and may reduce risk of type 2 diabetes and cardiovascular disease.